Vaccine failure, according to the fact sheet provided by the DOH, "refers to the development of the specific disease being prevented by the vaccine in a person who is appropriately and fully vaccinated, taking into account the incubation period of the disease and the normal delay for the protection to be acquired as a result of immunization."

Domingo clarified that vaccine failure was not seen in all the 830,000 children vaccinated with Dengvaxia.

"Three cases out of of 830,000 is a very small number. The vaccine failure is for particular cases," he said.

Dr. Juliet Sio-Aguilar, professor and chair of Pediatrics of the Philippine General Hospital said all three cases are confirmed as dengue shock syndrome.

Aguilar said they found out that two patients who completed the three doses of the dengue vaccine still died.

When the blood sample was checked, the doctor who attended to the patient found out that the NS1, the test to check if the patient has dengue infection, turned out positive. However, the antibodies for both IgG and IgM were negative.

In all these three cases, Aguilar said they recommend tissue evaluation so they can do more tests.

During the presentation of the findings of the UP-Philippine General Hospital Dengue Investigative Task Force (DITF) on the deaths of 14 children given from one to three doses of Dengvaxia, it was found out that aside from the 3 cases of dengue deaths, 3 others had nothing to do with Dengvaxia.

The drug was given to about 830,000 children in Metro Manila, Southern Luzon, Central Luzon and Central Visayas under the state's dengue immunization program before it was shut down late last year over the Sanofi warning.

"These findings strengthen the decision made by the Secretary to stop the vaccinations. We feel that Dengvaxia is not ready for mass immunization," Domingo said.

The DOH will forward the results to the Department of Justice to help in building a case against those responsible for the controversial dengue immunization program.